Opposed piston type steam engine



Oct. 4 P. VARIS 2,330,937

OPPOSED PISTON TYPE STEAM ENGINE Filed Feb. 25, 1942 3 Sheets-Sheet l ZZZ-6.1

.36 J6 1L i Z /6 J9 .22 2 w 7" w v INVENTOR. PE7'R l AR/s.

v BY K j 0a. 5, 1943. VARIS 2,330,937

OPPOSED PISTON TYPE STEAM ENGINE Art "013M33 Oct. 5, 1943. P. vARls' OPPOSED PISTON TYPE STEAM ENGINE 3 Sneets-Sheet 3 Filed Feb. 25, 1942 FIG. 4.

Patented Oct. 5, 1943 2 Claims; Jun-e100 invention. relates to! improvements in steam ens-ineshndmbre,specificallyto a steam engine. having a plurality of opposed pistons re cipmcably perating in a. single. ylinder.

One. 01 the features of. the invention'resi s in. a steam engine in which e piston tray-cl i relativelyshortto effect ajaster speed oi engine llli mfibnlj e v. a a

Anotherfeature. of the invention is. to provide a steam engine capable of, Producing relatively great power. in proportionLto the size of the engine, ,p f A. still further ieature ofithe invention isjto provide a steam engine embodying a primary double, head' power piston directly connected to a crank'shaft and a secondary,opposed piston interposed; between. the heads of the double pis; e

tort and cooperating 'therewith to define alter w nately functioning expansion steam chambers, power-being" simultaneously imparted to theprimar-y andsecondary-pistons by the expansion of steam alternately admitted to the steam expansion chambers; there being mechanical means by which the power-of the secondary piston is trz'n'isferredtothe primarydouble piston to effect an increase-in power output off the" engine. Other featuresof the'inventionare to provide an opposed-piston type' steam engine which is simple of construction and operation; easy of piston-repair and replacement and smooth run nine and quietoi operation. p

'Otherfeatures of the invention will become apparent as 'the fo1low ing specification is read in conjunction with theaccompanying drawings, inwhicht" t Figure 1 iso top plan new of a steam engine constructed in accordance withthe invention; Figure 2 isa, vertical longitudinal sectional view on the linedmrof l igure 1', and illustrating the". opposed; pistons atsubstantijally'the limit of thein'stroke in onev direction infull lines; and at: the, extreme oft'their stroke in an opposite direction in dotted lines.

Figure 3 'is' a horizontal sectional view on-ithe line 3-3fofi figured;

Figure." 4 is at verticali longitudinal sectional view of a modifiedzfornt off the, invention. illusing he: Opposed: pistonsjat substantially the limit of their stroke-in: one direction: in .full lines; and at the extreme: limit of: their stroke in.- an! opposite directionin dotted: lines.

In. the drawingsI have: illustrated lilyppose piston; type steam engine to; as bein rvertically disposed, and I shall describe-hm termsqcone sietent tnerewithrbut it is. be understood that the engine-may be horizontally mounted. if desircdjwithout departing from the spirit of, the invention. 1 1 v Ihe steam engine designated in its entirety by the numer.al L0, includes a vertical cylinder ll whichfi pen atits, top: and bottom. Suit ably spgece "stean lport l2 andljls are provided in thejhll 'oithe cylinder theopening and ,c1osin'g; oiTwhich for. the admission andexhaust of steam iscontrolled by the double slide valve l4 disp osed'pwithin asteiim, chest l5. The steam chest i5; isof conventional construction and inc udes a steam inlet 16 and a steam exhaust l1. Elllfihi' explanation of the construction and operationoif the slide valve [4 williollow.

Reciprocaple within the cylinder I l is a double primary power piston A which. includes a lower piston headl L8,; and an upper piston head I9, fixedly: p onnetzted together indefinite, spaced relationjby; two 1'0d's, 2020 disposed equidistantly, from; and diametrically disposed. relative to i the] axis ofthe piston heads I8 and I9. The rods ZQZflpass through openings in the piston heads and to. which they are fixedly, connected. Thefconnectionbetween the'rods 20.2IJ and the piston head I8' comprises a flange 2i formed integral witheach rod and abutting the innerside of the piston head, and a clamping nut 22 threadegi' to thefrod and screwed tight against the outer sidevof the piston head l8. The rods 20:40am connected to the piston head [8 by" pairs ofclamping nuts 22"- -2 2 threaded tdth'e rodsah-d; tightly aiouttingthe inner and outer sides. or the said head.

The lower piston head l-B- is connected hy'a wrist-pin connection 23 to the top end of'a connecting rod 24, The lower end of thelconnzcting'r od fl is connectedhy a bearing 25 to the crank ze of a 'crankshaft 21-, the latter being rotata blyio'urnaled-"in fixed bearings 23; From thejd escriptionfthusfar; it will be understood Reciprocally: disposed within the cylinder H intermediate: the" piston heads l3 and IQ of the douhlespower" piston A lis an opposed piston B comprising a: piston headtfl'having spaced openings 3 I3l therein through which the rods 20-20 freely pass. Leakage; of steamthroughv the a openis preyented by packing glands 3-2 which are carried by the piston head 30 and which surround the rods 20-20. Fixedly connected to the piston head 30 axially thereof and rising vertically'therefrom is the lower'end of a piston rod 33. The rod 33 freely passes through a central Opening 34 in the upper piston head l9, and the upper end of said rodextends beyond the piston head l9 for a reason to be hereinafter appreciated. Leakage of steam through the opening 34 is preventedby apacking gland 35 carried by the outer side of the piston head I9 and which surrounds the rod 33.

The upper end of the piston rod 33 is mechan l Till cally connected to the double power piston A'for the purpose of transferring power from the piston B to the power piston unit A during operation 'o'fl;

the engine. The connecting mechanisminclude's. diametrically opposed rock-levers 36 pivotally moimted in bearings 3'|--31' disposedIat-the top of the cylinder II. The rock-levers extend radially with respectto th'e axis of the cylinder andhave their inner ends respectively flexibly connectedto the top ends of the rods 2 20 by meansof short pivotal links 383B. The outer ends of .the rock-levers are pivotallyconnected to rods 33-39. Each"rod ,39"is sectionaland embodies a turnbuckle 40 for facilitatingadjustment crank shaft 27. A rod 48 is fixed to the lower end of the slide valve I4 and is slidably mounted in a bearing 49 extending from one of the bearings 28. The lower end of the rod 48 freely rides against the periphery of the cam 41.

In Figure l of the drawings, the piston heads 18 and 30 are nearing the limit of their movement toward each other, the crank being approximately on center. The piston I9 is at the top of the cylinder ,at approximately the limit of its upward movement. As the crank 26 moves past center, the inlet passage 43 of the steam slide valve registers with the port I! and simultaneously the exhaust passage 46 registers with the p'ort I31 "Thus steam from the steam chest I 5 enters the steam chamber C defined by the close- :lyQpositionedpiston heads l8 and 30, and simultaneously the expandedsteam from the steam of the length of the same.) 'Thepther endsv of the rods 39-39 are respectively jpivotally: con-'- nected to the endsfof ahead 4| which is fixedly attachedto or integral with the top end of the connecting rod 33. Thus it, will be understood thatsas the intermediate piston head moves up and downrelative tothefixedlyspaced piston 7 heads 18 and i9, power from the. piston head 30 will betransferred to the double power piston A and impart additional power thereto.-

The space between the piston head 1.8 and opposed piston head 30 constitutes a' lower steam expansion chamber C which isreduced in size as the piston heads l8 and 30 move toward each other, and becomes enlargedas they move away from each other by the expansion of steam admitted to the chamber." The port I! constitutes the steam inlet and outlet for the lower steam chamber C. A i a The space between the upper piston head l9 and the piston head 30 constitutes an upper steam expansion chamber D which is reducedin size as the piston heads l9 and .30 movetoward each other, and become enlargedas they move away from each other by the expansion of steam in the steam chamber D. The port l3 constitutes the steam inletand exhaust-for the steam chamber D. a 7 E ,Referring back to the slide valvel4, the same is provided with suitably spaced steam inlet pas-,

sages 42 and 43 for timed alternate-registration with the ports' [2 and 13 respectively as the opposed intermediate piston head reaches the limit of its movement in opposite directions. The inlet passages 42 and 43 openiinto' thesteam chest 15.

chamber D is exhausted through the port l3, passage 46 to the steam exhaust pipe |'l. The valve l4 moves to' closetheports l2 andj l 3 whereupon the expansion ,of the steam in the' chamber'C forcibly moves the pistons l8 and30 away from each other.v Powerfrom the, piston A is therefore directly transmitted from the piston'head l8, connecting rod 24, andcrankZG to the crank shaft 21. Power'from the upstroke of the piston head 30 is indirectly transferred from the piston Bfto crankshaftllthrough thepiston A bythe mechanical connecting means consisting of thereonnecting rod 33, rods 39,rock levers 36 and flexible coupling links 38 tothe rods 20, Similarly, the power is transmitted "from 'pistor'isA and B during the power upstroke of the piston A and down- .stroke of th'e'piston B. Power for the stroke just 7, mentioned is obtained by the admission of steam through the port l3 by registration of the inlet passage 43 therewith, at which time the piston heads 30 and 19v are in relatively close; relation, reducing the size ofzthe chamber D, and the piston head I8is at the lower end of the cylinder 1 l. as illustrated in dotted lines. Also, at this time the'exhaus't passage 45 is in registerwith the port [2 to exhaust steam f-romthe chamber C. Thus bythetiming movementsof the steam slide valve I4 bythe actuationlof the cam 41, the-pistons 18, I9 and 30 will reciprocateinthe manner hereinbefore described, that is, power from'the double The slidevalve isalso provided with suitably spaced exhaust passages-45 and 46 which alternately register with'the -ports l2 and ;l3 respectively in timedrelation to exhaust .;ste'am=-from the chambers C and D at the limit of theexpansion strokes of thepistons. The exhaust passages 45 and 46 register witha manifold -or exhaust outlet leading to-the commonexhaust lT'when the same are respectively registering, with the ports I! and l3.

'I'hemovement of the valve'l4 is timedand mechanically controlledtby'a'cam 41 fixed to the piston A and opposed piston-B is transmitted to the crank shaft twice on each revolution thereof.

From the foregoingdescription it will'be understood that the steam engineill is relatively simple and compact inconstruction; that the ,pistons are accessible for easy removal for replacement of parts and repair; and that the strokes of the pistonsare relatively short'which is inducive of faster speed and smooth operation. I

In practice, the exhaust from the exhaust'pipe ll before passingto a'condenser or to the atmosphere, maybe connected by means'of a valve, to

a series ,of three cylinders, the first cylinder being known as H. P. (high pressure), the second LP. (intermediate pressure), and the third, L. P. (low pressure). However,if a single cylindersteam engine is constructed in accordance with this invention, "the exhaust is direct to a steam condenser or to the atmosphere.

'In Figure 4 there is shown a modified form of the invention in which the fixed coupling means between the piston heads of the double power piston is disposed exteriorly ofthe cylinder instead of within'the cylinder as shown in Figure 2. In this form, the cylinder l I, steam chest l5, and crank shaft 21 are the same as in the'form shown the cylinder I I.

spaced piston heads of the power piston A are designated I8a and We, the piston head 18a being directly connected to the crank shaft 21 by the connecting rod 24. Connected to the piston head 18a and extending upwardly therefrom is a rod 33a. The rod 33a issecured to the head I80, axially thereof and is connected thereto by nuts 50-50 which are threaded to the threaded portion 51, the said nuts tightly abutting the respective opposed sides of the head. The rod 33a extends upwardly through an oversize axial opening 53 in the head [9a, the upper end of the said rod being screw threaded as at 54 to which a cross arm Ma is connected. The threaded end 54 passes through the cross arm and has clamping nuts 55-55 threaded thereto and tightly fitting against the respective opposed sides of the cross arm. Spacer rods Zoo-20a connect the cross arm Ma and piston head We, said rods being disposed, equi-distantly from and diametrically disposed relative to the axis of the center rod 33a. The ends of the rods filo-26a are threaded to receive nuts 56 which tightly secure the rods to the cross arm Ma. and piston head l9a.

Slidably telescoping the rod 33a is a tubular rod 51, the inner end of which is externally screw threaded for threading engagement with a central threaded aperture 58 provided in the intermediate opposed piston head 38a. Clamping nuts 59 are threaded to the tubular rod 51 and tightly engage the walls of opposed counter-sinks inthe opposed sides of the piston head 30a. The upper end of the rod 51 freely passes through the openings 53 to extend beyond the piston head F911, and this extending end of the rod 51 is proprovided with a head 60; The joint betweenthe head 60 and the rod 33a is sealed by a packing gland 6|. A similar packing gland 62seals the joint between the tubular rod 51 and the walls of the opening 53 to prevent leakage of steam from the steam chamber D, said chamber being formed by the opposed piston heads l9a'and 33a. The second steam chamber C is formed between the piston head 30a and the piston head l8a. From the description thus far of the modified form of engine it will be understood that the piston heads [8a, 19a, and the cross arm Ma may reciprocate as a single unit, and that the single intermediate piston head 30a is reciprocable relative thereto. However, power from the piston 30a is transferred to the double or power piston A by mechanical means disposed exteriorly of This mechanical means includes rock-levers 36a-36a pivotally mounted in bearings 3131' disposed in diametrically opposed relation at the top of the cylinder II. The rock levers extend radially with respect to the axis of the cylinder and have their inner ends pivotally connected to the upper ends of links 38a-38a, said links having their lower ends pivoted to ears 63 extending from the head 60. The inner ends of the levers 36a are bifurcated or forked to permit them to clear the rods 20a. 'Pivoted to the outer forked ends of the rock levers 36a--36a are the lower ends of links 39a39.a, the upper ends of said links being pivotally connected to the cross arm 4 la.

The operation of the modified form of the invention as set forth in Figure 4 is the same as that'previously described, except the mechanical means by which the power from the intermediate piston head is transmitted to the double head piston A. As the piston head 30a reciprocates under, the alternate expansion of steam in the steam chambers C and D, power therefrom is transmitted to the cross arm Ma by the actuation of the links 38a -38a, rock levers 36a-38a, and links 39a39a to the cross arm Ma, and thence from the cross arm directly to the piston head l9a by the connecting rods 20o--2Ela and to the piston head i811 by the piston rod 33a.

By the novel construction and arrangement of parts as set forth in the modification shown in Figure 4, the pistons and their connecting parts are readily accessible for disconnection and reassembly when repair or replacement of such parts becomes necessary. The thread and nutconnections between the cross arm 41a and the rods 20a-20a, and 33a facilitates adjustment of the strokes of the piston heads when wear between the levers and links occur.

While I have shown and described what I consider to be the preferred embodiments of my invention, I wish it to be understood that such changes in design and construction as come within the scope of the appended claims may be resorted to if desired without departing from the spirit of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States: a I

1. Ina steam engine, a cylinder open at both ends, a primary piston slidable in said cylinder comprising an upper and lower piston heads, a

connecting rod fixed to the lower piston head and freely passing through the upper piston head and extending therebeyond, a cross arm fixed to theextending end of. said rod, an intermediate piston head disposed within said cylinder between .said upper and lower piston heads, rods connecting the cross arm to the upper piston head, a tubular rod slidably telescoping the connecting rod andhaving its inner end fixedly connected to said intermediate piston head and its other end freely passing through and beyond the upper piston head, the spaces between opposite sides of the intermediate piston head and the upper and lower piston heads constituting separate steam chambers, a pair of spaced ports in the cylinder opening into the respective steam expansion chambers, means for alternately admitting steam to the expansion chambers and for exhausting the same therefrom, means connecting the free extending end of the tubular rod to the cross arm for transmitting power from the intermediate piston to the primary piston, a crank shaft, and

'a connecting rod connecting the lower piston 

